1. Field of the Invention
The present invention relates to a display apparatus with an image-capturing function, an image processing apparatus, an image processing method, and an image display system.
2. Description of the Related Art
In general, when display apparatuses with an image-capturing function are used in mixed realty (MR) environments, images captured by image pickup devices are loaded into a personal computer (PC) to perform distortion correction processing to correct distortion caused by the image pickup devices. The display apparatuses with an image-capturing function are hereinafter referred to as “head mounted displays (HMDs).” The HMDs are not limited to head-mounted type apparatuses, and may include hand-held type apparatuses such as binoculars.
The PC combines computer graphics (CG) images with the corrected images, and supply the combined images to display devices for display. A correction technique of the related art for distortion caused by the image-capturing system is disclosed in S. Uchiyama et al., “MR Platform: A basic body on which mixed reality applications are built,” Proc. IEEE/ACM Internat. Symp. on Mixed and Augmented Reality (ISMAR 2002), pp. 246-253, 2002.
Correction for distortion caused by the display system of the HMDs, on the other hand, has not been much taken into account, and there has been a problem in that displayed images are distorted when the display system of the HMDs has a wide angle field of view. If distortion correction for the display system is simply introduced to compensate for this distortion, images corrected for distortion caused by the image-capturing system are again corrected for distortion caused by the display system.
Therefore, when images captured using the HMDs are to be directly observed using the display devices of the HMDs, an arithmetic operation for distortion correction is performed twice. There arises a problem in that the quality of finally displayed images is lowered by arithmetic errors.
Another problem occurs when HMDs have different distortion correction functions, for example, when an HMD has a built-in distortion correction function for the image-capturing system and another HMD does not have such a function. In this case, even if PCs uniformly perform correction processing, distortion-corrected images are further subjected to distortion correction processing, and displayed images may be distorted.